Radio communication apparatus, method, program, non-transitory computer readable recording medium, and system

ABSTRACT

In order to enable control related to radio communication to be performed more appropriately when radio transmission schemes coexist, a radio communication apparatus according to an example aspect of the present invention includes a radio communication processing unit configured to perform communication using a first radio transmission scheme within a frequency band, wherein the radio communication processing unit is configured to perform communication using a second radio transmission scheme within a bandwidth part of the frequency band, radio resources within the bandwidth part being allocable for communication using the second radio transmission scheme.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation application of U.S. patentapplication Ser. No. 16/633,022 filed on Jan. 22, 2020, which is aNational Stage Entry of international application PCT/JP2018/018286filed on May 11, 2018, which claims the benefit of priority fromJapanese Patent Application 2017-143394 filed on Jul. 25, 2017, thedisclosures of all of which are incorporated in their entirety byreference herein.

BACKGROUND Technical Field

The present invention relates to a radio communication apparatus, amethod, a program, a non-transitory computer readable recording medium,and a system.

Background Art

In Long Term Evolution (LTE) standardized in the 3rd GenerationPartnership Project (3GPP), discrete Fourier transform spread orthogonalfrequency division multiplexing (DFT-S-OFDM) is adopted as a radiotransmission scheme to be used for uplink data transmission andreception (NPL 1). In DFT-S-OFDM, mapping of a discrete Fouriertransform (DFT) output to an inverse fast Fourier transform (IFFT) inputis limited to subcarriers that are contiguous on a frequency axis, togenerate a single-carrier signal having a low peak power, which enableswide coverage.

On the other hand, currently, standardization of New Radio (NR)supporting a wider frequency band than that of LTE is underway by 3GPP.In NR, to enable more flexible radio resource allocation, orthogonalfrequency division multiplexing (OFDM) is adopted as a radiotransmission scheme to be used for uplink data transmission andreception. OFDM is a multi-carrier transmission scheme and is highlyflexible with respect to allocation since radio resources that arediscontiguous on a frequency axis are allocated. However, a peak powerin this scheme is higher than that in a single-carrier transmissionscheme, and hence the coverage results in being small.

To enlarge the coverage, in 3GPP, DFT-S-OFDM is adopted as a radiotransmission scheme to be used for uplink data transmission andreception in NR, together with OFDM (NPL 2). Note that PTL 1 discloses atechnique for using DFT-S-OFDM and clustered-DFT-S-OFDM.

CITATION LIST Patent Literature

[PTL 1] JP 2011-142404 A

Non Patent Literature

[NPL 1] 3GPP TS 36.211 (V8.6.0), “Evolved Universal Terrestrial RadioAccess (E-UTRA); Physical channels and modulation”, Mar. 2009.

[NPL 2] 3GPP TR 38.802 V1.2.0, “3rd Generation Partnership Project;Technical Specification Group Radio Access Network; Study on New Radio(NR) Access Technology; Physical Layer Aspects (Release 14)”, February2017.

SUMMARY Technical Problem

Since OFDM and DFT-S-OFDM are both adopted as radio transmission schemesas described above, OFDM transmission and DFT-S-OFDM transmission maycoexist within the same transmission time interval. When such radiotransmission schemes coexist without any restriction, control related toradio communication may be difficult or inefficient.

An example object of the present invention is to provide a radiocommunication apparatus, a method, a program, a non-transitory computerreadable recording medium, and a system that enable control related toradio communication to be performed more appropriately when radiotransmission schemes coexist.

Solution to Problem

A radio communication apparatus according to an example aspect of thepresent invention includes a radio communication processing unitconfigured to perform communication using a first radio transmissionscheme within a frequency band, wherein the radio communicationprocessing unit is configured to perform communication using a secondradio transmission scheme within a bandwidth part of the frequency band,radio resources within the bandwidth part being allocable forcommunication using the second radio transmission scheme.

A method according to an example aspect of the present inventionincludes performing communication using a first radio transmissionscheme within a frequency band, and performing communication using asecond radio transmission scheme within a bandwidth part of thefrequency band, radio resources within the bandwidth part beingallocable for communication using the second radio transmission scheme.

A program according to an example aspect of the present invention is aprogram that causes a processor to execute performing communicationusing a first radio transmission scheme within a frequency band, andperforming communication using a second radio transmission scheme withina bandwidth part of the frequency band, radio resources within thebandwidth part being allocable for communication using the second radiotransmission scheme.

A non-transitory computer readable recording medium according to anexample aspect of the present invention is a non-transitory computerreadable recording medium having recorded thereon a program that causesa processor to execute performing communication using a first radiotransmission scheme within a frequency band, and performingcommunication using a second radio transmission scheme within abandwidth part of the frequency band, radio resources within thebandwidth part being allocable for communication using the second radiotransmission scheme.

A system according to an example aspect of the present inventionincludes a base station, and a terminal apparatus, wherein the basestation is configured to perform communication using a first radiotransmission scheme within a frequency band, and perform communicationusing a second radio transmission scheme within a bandwidth part of thefrequency band, radio resources within the bandwidth part beingallocable for communication using the second radio transmission scheme,and wherein the terminal apparatus is configured to performcommunication using the first radio transmission scheme within thefrequency band, and perform communication using the second radiotransmission scheme within the bandwidth part.

Advantageous Effects of Invention

According to the present invention, it is possible to perform controlrelated to radio communication more appropriately when radiotransmission schemes coexist. Note that, according to the presentinvention, instead of or together with the above effects, other effectsmay be exerted.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of signal generation in DFT-S-OFDM;

FIG. 2 is a block diagram of signal generation in OFDM;

FIG. 3 is an explanatory diagram for illustrating an example of resourceblock allocation;

FIG. 4 is an explanatory diagram illustrating an example of a schematicconfiguration of a system according to a first example embodiment;

FIG. 5 is a block diagram illustrating an example of a schematicconfiguration of a base station according to the first exampleembodiment;

FIG. 6 is a block diagram illustrating an example of a schematicconfiguration of a terminal apparatus according to the first exampleembodiment;

FIG. 7 is an explanatory diagram for illustrating an example of abandwidth part according to the first example embodiment;

FIG. 8 is an explanatory diagram for illustrating a different example ofthe bandwidth part according to the first example embodiment;

FIG. 9 is an explanatory diagram illustrating an example ofidentification information of regions according to the first exampleembodiment;

FIG. 10 is an explanatory diagram for illustrating an example of localidentification information according to the first example embodiment;

FIG. 11 is an explanatory diagram for illustrating an example ofidentification information of radio resources in a tree-basedrepresentation;

FIG. 12 is an explanatory diagram for illustrating a different exampleof local identification information according to the first exampleembodiment;

FIG. 13 is a sequence diagram for illustrating an example of a schematicflow of communication processing according to the first exampleembodiment;

FIG. 14 is an explanatory diagram for illustrating an example ofresource allocation according to a first example alteration of the firstexample embodiment; and

FIG. 15 is a block diagram illustrating an example of a schematicconfiguration of a radio communication apparatus according to a secondexample embodiment.

DESCRIPTION OF THE EXAMPLE EMBODIMENTS

Hereinafter, example embodiments of the present invention will bedescribed in detail with reference to the accompanying drawings. Notethat, in the Specification and drawings, elements to which similardescriptions are applicable are denoted by the same reference signs, andoverlapping descriptions may hence be omitted.

Descriptions will be given in the following order.

1. Related Art

2. Overview of Example Embodiments of the Present Invention

3. First Example Embodiment

-   -   3.1. Configuration of System    -   3.2. Configuration of Base Station    -   3.3. Configuration of Terminal Apparatus    -   3.4. Technical Features    -   3.5. Example Alteration

v4. Second Example Embodiment

-   -   4.1. Configuration of Radio Communication Apparatus    -   4.2. Technical Features

1. Related Art

As techniques related to example embodiments of the present invention,DFT-S-OFDM and OFDM will be described.

(1) DFT-S-OFDM

FIG. 1 is a block diagram of signal generation in DFT-S-OFDM. Withreference to FIG. 1, discrete Fourier transform (DFT) (11), subcarriermapping (13), inverse fast Fourier transform (IFFT) (15), and cyclicprefix (CP) addition (17) are performed on a modulated signal.

In DFT-S-OFDM, mapping of a DFT output to an IFFT input is limited tosubcarriers that are contiguous on a frequency axis, to generate asingle-carrier signal having a low peak power, which enables widecoverage.

(2) OFDM

FIG. 2 is a block diagram of signal generation in OFDM. With referenceto FIG. 2, subcarrier mapping (21), inverse fast Fourier transform(IFFT) (23), and cyclic prefix (CP) addition (25) are performed on amodulated signal.

OFDM is a multi-carrier transmission scheme and is highly flexible withrespect to radio resource allocation since radio resources that arediscontiguous on a frequency axis are allocated. However, a peak powerin this scheme is higher than that in a single-carrier transmissionscheme, and hence the coverage results in being small.

2. Overview of Example Embodiments of the Present Invention

First, an overview of example embodiments of the present invention willbe described.

(1) Technical Issues

In 3GPP, DFT-S-OFDM as well as OFDM are adopted as radio transmissionschemes to be used for uplink data transmission and reception in NR, forcoverage expansion. Since OFDM and DFT-S-OFDM are both thus adopted asradio transmission schemes, OFDM transmission and DFT-S-OFDMtransmission may coexist within the same transmission time interval.When such radio transmission schemes coexist without any restriction,control related to radio communication may be difficult or inefficient.

As an example, if each base station allows mixture of OFDM transmissionand DFT-S-OFDM transmission with less restriction, interference controlor coordinated multi-point transmission/reception (CoMP) between basestations may be difficult.

As a different example, radio resources that are discrete on a frequencyaxis are allocated for transmission in OFDM, which is a multi-carriertransmission scheme, so that small discrete radio resources remain,which may consequently disable allocation of sufficient radio resourcesfor transmission in DFT-S-OFDM, which is a single-carrier transmissionscheme. In other words, allocation of radio resources for DFT-S-OFDMtransmission may be limited.

Specifically, for example, as illustrated in FIG. 3, resource block (RB)#0, RB #1, RB #4, and RB #6 are allocated for a UE employing OFDM, andRB #2, RB #3, RB #5, and RB #7 remain. Here, a UE employing DFT-S-OFDMhas a restriction that only RBs that are contiguous on a frequency axisare allocable, and hence only two RBs, RB #2 and RB #3, are allocatedfor this UE at maximum. In this way, allocation of radio resources forDFT-S-OFDM transmission may be limited.

As a still different example, when DFT-S-OFDM transmission is performedin a limited manner, the information amount of resource allocationinformation is maintained if no restriction is imposed on radioresources to be allocated for DFT-S-OFDM, and this may cause signalingto be inefficient.

Hence, it is desirable to perform control related to radio communicationmore appropriately when radio transmission schemes coexist.

(2) Technical Features

In the example embodiments of the present invention, for example, aradio communication apparatus (a base station/a terminal apparatus)performs communication using a first radio transmission scheme (e.g.,OFDM) within a frequency band. Moreover, the radio communicationapparatus (the base station or the terminal apparatus) performscommunication using a second radio transmission scheme (e.g.,DFT-S-OFDM) within a bandwidth part of the frequency band, radioresources within the bandwidth part being allocable for communicationusing the second radio transmission scheme.

With this, it is possible, for example, to perform control related toradio communication more appropriately when radio transmission schemescoexist.

Note that the above-described technical features are concrete examplesof the example embodiments of the present invention, and the presentexample embodiments of the present invention are, of course, not limitedto the above-described technical features.

3. First Example Embodiment

Next, a description will be given of a first example embodiment of thepresent invention with reference to FIGS. 4 to 14.

3.1. Configuration of System

First, with reference to FIG. 4, an example of a configuration of asystem 1 according to the first example embodiment will be described.FIG. 4 is an explanatory diagram illustrating an example of a schematicconfiguration of the system 1 according to the first example embodiment.With reference to FIG. 4, the system 1 includes a base station 100 andterminal apparatuses 200.

Although two terminal apparatuses 200 (a terminal apparatus 200A and aterminal apparatus 200B) are illustrated in FIG. 4, the system 1 mayinclude three or more terminal apparatuses 200. Here, when the twoterminal apparatuses 200 need to be distinguished from each other, theterminal apparatuses 200 are described as the terminal apparatus 200Aand the terminal apparatus 200B. However, when the two terminalapparatuses 200 need not be distinguished from each other, the terminalapparatuses 200 are simply described as the terminal apparatus(es) 200.

The system 1 is, for example, a system conforming to Third GenerationPartnership Project (3GPP) standards/specifications. More specifically,for example, the system 1 may be a system conforming to fifth-generation(5G)/New Radio (NR) standards/specifications. The system 1 is, ofcourse, not limited to these examples.

(1) Base Station 100

The base station 100 is a radio access network (RAN) node and isconfigured to perform radio communication with terminal apparatuses(e.g., the terminal apparatuses 200) located in the coverage area of thebase station 100.

For example, the base station 100 may be a generation Node B (gNB) in5G. The base station 100 may include a plurality of units (or aplurality of nodes). The plurality of units (or the plurality of nodes)may include a first unit (or a first node) configured to perform higherprotocol layer processing and a second unit (or a second node)configured to perform lower protocol layer processing. As an example,the first unit may be referred to as a center/central unit (CU), and thesecond unit may be referred to as a distributed unit (DU) or an accessunit (AU). As another example, the first unit may be referred to as adigital unit (DU), and the second unit may be referred to as a radiounit (RU) or a remote unit (RU). The digital unit (DU) may be a baseband unit (BBU), and the RU may be a remote radio head (RRH) or a remoteradio unit (RRU). The terms for the first unit (or the first node) andthe second unit (or the second node) are, of course, not limited tothese examples. Alternatively, the base station 100 may be a single unit(or a single node). In this case, the base station 100 may be one of theplurality of units (e.g., either one of the first unit and the secondunit) or may be connected to another unit of the plurality of units(e.g., the other one of the first unit and the second unit).

(2) Terminal Apparatus 200

Each terminal apparatus 200 performs radio communication with a basestation. For example, the terminal apparatus 200 performs radiocommunication with the base station 100 in a case of being located inthe coverage area of the base station 100. For example, the terminalapparatus 200 is a user equipment (UE).

3.2. Configuration of Base Station

Next, with reference to FIG. 5, a description will be given of anexample of a configuration of the base station 100 according to thefirst example embodiment. FIG. 5 is a block diagram illustrating anexample of a schematic configuration of the base station 100 accordingto the first example embodiment. With reference to FIG. 5, the basestation 100 includes a radio communication unit 110, a networkcommunication unit 120, a storage unit 130, and a processing unit 140.

(1) Radio Communication Unit 110

The radio communication unit 110 wirelessly transmits and/or receives asignal. For example, the radio communication unit 110 receives a signalfrom a terminal apparatus and transmits a signal to the terminalapparatus.

(2) Network Communication Unit 120

The network communication unit 120 receives a signal from a network andtransmits a signal to the network.

(3) Storage Unit 130

The storage unit 130 temporarily or permanently stores programs(instructions) and parameters for operations of the base station 100 aswell as various data. The program includes one or more instructions foroperations of the base station 100.

(4) Processing Unit 140

The processing unit 140 provides various functions of the base station100. The processing unit 140 includes a radio communication processingunit 141 and a network communication processing unit 143. Note that theprocessing unit 140 may further include constituent elements other thanthese constituent elements. In other words, the processing unit 140 mayalso perform operations other than the operations of these constituentelements. Concrete operations of the radio communication processing unit141 and the network communication processing unit 143 will be describedlater in detail.

For example, the processing unit 140 (the radio communication processingunit 141) communicates with a terminal apparatus (e.g., the terminalapparatus 200) via the radio communication unit 110. For example, theprocessing unit 140 (the network communication processing unit 143)communicates with a different network node (e.g., a different basestation or core network node) via the network communication unit 120.

(5) Implementation Example

The radio communication unit 110 may be implemented with an antenna, aradio frequency (RF) circuit, and the like, and the antenna may be adirectional antenna. The network communication unit 120 may beimplemented with a network adapter and/or a network interface card, andthe like. The storage unit 130 may be implemented with a memory (e.g., anonvolatile memory and/or a volatile memory) and/or a hard disk, and thelike. The processing unit 140 may be implemented with one or moreprocessors, such as a baseband (BB) processor and/or a different kind ofprocessor. The radio communication processing unit 141 and the networkcommunication processing unit 143 may be implemented with the sameprocessor or may be implemented with separate processors. The memory(storage unit 130) may be included in the one or more processors or maybe provided outside the one or more processors.

The base station 100 may include a memory configured to store a program(instructions) and one or more processors that can execute the program(instructions). The one or more processors may execute the program andthereby perform operations of the processing unit 140 (operations of theradio communication processing unit 141 and the network communicationprocessing unit 143). The program may be a program for causing theprocessor(s) to perform operations of the processing unit 140(operations of the radio communication processing unit 141 and thenetwork communication processing unit 143).

Note that the base station 100 may be virtual. In other words, the basestation 100 may be implemented as a virtual machine. In this case, thebase station 100 (the virtual machine) may operate as a physical machine(hardware) including a processor, a memory, and the like, and a virtualmachine on a hypervisor.

3.3. Configuration of Terminal Apparatus

Next, with reference to FIG. 6, an example of a configuration of theterminal apparatus 200 according to the first example embodiment will bedescribed. FIG. 6 is a block diagram illustrating an example of aschematic configuration of the terminal apparatus 200 according to thefirst example embodiment. With reference to FIG. 6, the terminalapparatus 200 includes a radio communication unit 210, a storage unit220, and a processing unit 230.

(1) Radio Communication Unit 210

The radio communication unit 210 wirelessly transmits and/or receives asignal. For example, the radio communication unit 210 receives a signalfrom a base station and transmits a signal to the base station.

(2) Storage Unit 220

The storage unit 220 temporarily or permanently stores programs(instructions) and parameters for operations of the terminal apparatus200 as well as various data. The program includes one or moreinstructions for the operations of the terminal apparatus 200.

(3) Processing Unit 230

The processing unit 230 provides various functions of the terminalapparatus 200. The processing unit 230 includes a radio communicationprocessing unit 231. Note that the processing unit 230 may furtherinclude constituent elements other than this constituent element. Inother words, the processing unit 230 may also perform operations otherthan the operations of this constituent element. Concrete operations ofthe radio communication processing unit 231 will be described later indetail.

For example, the processing unit 230 (the radio communication processingunit 231) communicates with a base station (e.g., the base station 100)via the radio communication unit 210.

(4) Implementation Example

The radio communication unit 210 may be implemented with an antenna, aradio frequency (RF) circuit, and the like. The storage unit 220 may beimplemented with a memory (e.g., a nonvolatile memory and/or a volatilememory) and/or a hard disk, and the like. The processing unit 230 may beimplemented with one or more processors, such as a baseband (BB)processor and/or a different kind of processor. The memory (storage unit220) may be included in the one or more processors or may be providedoutside the one or more processors. As an example, the processing unit230 may be implemented in a system on chip (SoC).

The terminal apparatus 200 may include a memory configured to store aprogram (instructions) and one or more processors that can execute theprogram (instructions). The one or more processors may execute theprogram and thereby perform operations of the processing unit 230(operations of the radio communication processing unit 231). The programmay be a program for causing the processor(s) to perform operations ofthe processing unit 230 (operations of the radio communicationprocessing unit 231).

3.4. Technical Features

Next, technical features of the first example embodiment will bedescribed with reference to FIGS. 7 to 13.

The base station 100 (the radio communication processing unit 141)performs communication using a first radio transmission scheme, within afrequency band. Moreover, the base station 100 (the radio communicationprocessing unit 141) performs communication using a second radiotransmission scheme within a bandwidth part of the frequency band, radioresources within the bandwidth part being allocable for communicationusing the second radio transmission scheme.

The terminal apparatus 200 (the radio communication processing unit 231)performs communication using the first radio transmission scheme, withinthe frequency band. Moreover, the terminal apparatus 200 (the radiocommunication processing unit 231) performs communication using thesecond radio transmission scheme, within the bandwidth part.

(1) Radio Transmission Scheme

For example, the first radio transmission scheme is a multi-carriertransmission scheme, and the second radio transmission scheme is asingle-carrier transmission scheme.

In other words, for example, the first radio transmission scheme is afirst multiplexing scheme, and the second radio transmission scheme is asecond multiplexing scheme.

More specifically, for example, the first radio transmission scheme isOFDM, and the second radio transmission scheme is DFT-S-OFDM.

(2) Communication

For example, the communication using the first radio transmission schemeand the communication using the second radio transmission scheme areeach communication of data channel.

For example, the communication using the first radio transmission schemeand the communication using the second radio transmission scheme areeach uplink communication. In this case, for example, the data channelis a physical uplink shared channel (PUSCH).

(3) Frequency Band

For example, the frequency band is a frequency band of a cellular system(or a mobile communication system). For example, the frequency band is asystem band or a component carrier of a cellular system.

(4) Bandwidth Part

For example, the bandwidth part has a bandwidth equal to or wider thantwo resource blocks. In other words, the bandwidth part includes two ormore contiguous resource blocks. The bandwidth part may have a bandwidthof six resource blocks. In this case, the bandwidth part may be referredto as a narrow band.

For example, the bandwidth part is a band within which radio resourcesare not allocable for communication of the first radio transmissionscheme. In other words, the base station 100 (the radio communicationprocessing unit 141) and the terminal apparatus 200 (the radiocommunication processing unit 231) perform communication using the firstradio transmission scheme within a region of the frequency band outsidethe bandwidth part and do not perform communication using the firstradio transmission scheme within the bandwidth part.

FIG. 7 is an explanatory diagram for illustrating an example of abandwidth part according to the first example embodiment. With referenceto FIG. 7, a frequency band including eight resource blocks (RBs #0 to#7) is illustrated. In this example, a band including RBs #2 to #5 isdesignated as a bandwidth part, radio resources within the bandwidthpart being allocable for communication using DFT-S-OFDM. In other words,in this example, the base station 100 performs communication usingDFT-S-OFDM within the bandwidth part including RBs #2 to #5. Theterminal apparatus 200 also performs communication using DFT-S-OFDMwithin the bandwidth part. In this case, radio resources within a bandincluding RBs #0 and #1 and a band including RBs #6 and #7 are allocablefor communication using OFDM. In other words, in this example, the basestation 100 performs communication using OFDM within the band includingRBs #0 and #1 and the band including RBs #6 and #7. The terminalapparatus 200 also performs communication using OFDM in these bands. Asan example, in a certain subframe, the terminal apparatus 200A performscommunication using DFT-S-OFDM within the bandwidth part (RBs #2 to #5),while the terminal apparatus 200B performs communication using OFDM indifferent regions (RBs #0, #1, #6, and #7).

According to this example, four RBs are allocable for a terminalapparatus using DFT-S-OFDM at maximum. In this way, it may be possibleto avoid a situation where allocation of sufficient radio resources fortransmission of the second radio transmission scheme (DFT-S-OFDM) is notpossible due to communication of the first radio transmission scheme(OFDM).

Note that a plurality of bandwidth parts, radio resources within thebandwidth parts being allocable for communication using the second radiotransmission scheme (e.g., DFT-S-OFDM), may be designated. For example,as in an example illustrated in FIG. 8, a band including RBs #0 and #1and a band including RBs #6 and #7 may be designated as two bandwidthparts, radio resources within the bandwidth parts being allocable forcommunication using DFT-S-OFDM.

The bandwidth part may have a bandwidth greater than 1.4 MHz (instead ofequal to or wider than two resource blocks).

As described above, the bandwidth part is a band of the frequency band,radio resources within the band being allocable for communication usingthe second radio transmission scheme, and may, in other words, beconsidered as a band reserved for communication using the second radiotransmission scheme. The bandwidth part may be referred to as otherterms such as a “frequency region” or a “radio resource region” (withoutbeing limited thereto).

(5) Transmission of Control Information to Terminal Apparatus (5-1)Bandwidth Part

For example, the base station 100 (the radio communication processingunit 141) transmits first control information indicating the bandwidthpart, to the terminal apparatus 200. The terminal apparatus 200 (theradio communication processing unit 231) then receives the first controlinformation from the base station 100.

Specifically, for example, the base station 100 (the radio communicationprocessing unit 141) transmits a radio resource control (RRC) messageincluding the first control information, to the terminal apparatus 200.The terminal apparatus 200 (the radio communication processing unit 231)then receives the RRC message. The RRC message may be system informationor a dedicated message.

Alternatively, the base station 100 (the radio communication processingunit 141) may transmit a medium access control (MAC) control elementincluding the first control information, to the terminal apparatus 200.The terminal apparatus 200 (the radio communication processing unit 231)may then receive the MAC control element.

In this way, for example, the terminal apparatus 200 can be notified ofthe bandwidth part. Moreover, as will be described later, it is possibleto reduce the overhead of resource allocation information, for example.Moreover, it is possible, for example, to change the bandwidth part.

As an example, the first control information includes identificationinformation of the first RB among the RBs included in the bandwidth part(#2 in the example in FIG. 7) and information indicating the number ofRBs included in the bandwidth part (four in the example in FIG. 7).

As a different example, identification information may be given to aregion consisting of a plurality of RBs, and the first controlinformation may include identification information of the region(s)included in the bandwidth part. For example, as in an exampleillustrated in FIG. 9, #0 may be given as identification information toa region consisting of RB #0 and RB #1; #1 may be given asidentification information to a region consisting of RB #2 and RB #3; #2may be given as identification information to a region consisting of RB#4 and RB #5; and #3 may be given as identification information to aregion consisting of RB #6 and RB #7. In this case, the first controlinformation may include #1 and #2 (pieces of identification informationof the regions included in the bandwidth part). Alternatively, the firstcontrol information may include identification information (#1) of thefirst region included in the bandwidth part and information (two)indicating the number of regions included in the bandwidth part.

(5-2) Radio Transmission Scheme

For example, the base station 100 (the radio communication processingunit 141) transmits, to the terminal apparatus 200, second controlinformation indicating which of the first radio transmission scheme andthe second radio transmission scheme is to be used. The terminalapparatus 200 (the radio communication processing unit 231) thenreceives the second control information from the base station 100.

Specifically, for example, the base station 100 (the radio communicationprocessing unit 141) transmits downlink control information (DCI)including the second control information, to the terminal apparatus 200.Alternatively, the base station 100 (the radio communication processingunit 141) may transmit a MAC control element including the secondcontrol information, to the terminal apparatus 200.

For example, the second control information is 1-bit information, andindicates, when indicating 0, to use the first radio transmission schemewhile indicating, when indicating 1, to use the second radiotransmission scheme. Alternatively, the second control information mayindicate, when indicating 0, to use the second radio transmission schemewhile indicating, when indicating 1, to use the first radio transmissionscheme.

This makes it possible, for example, to use a more preferable one of thefirst radio transmission scheme and the second radio transmissionscheme. Using DCI makes it possible to dynamically switch the radiotransmission scheme for each subframe. This switching may be performedfor each symbol or slot.

(5-3) Radio Resources

For example, the base station 100 (the radio communication processingunit 141) transmits, to the terminal apparatus 200, resource allocationinformation indicating radio resources allocated for the terminalapparatus 200. More specifically, for example, the base station 100 (theradio communication processing unit 141) transmits DCI including theresource allocation information, to the terminal apparatus 200.

For example, the radio resources within the bandwidth part has localidentification information for locally identifying the radio resourceswithin the bandwidth part. In this case, the base station 100 (the radiocommunication processing unit 141) transmits the local identificationinformation as the resource allocation information, to the terminalapparatus 200. The terminal apparatus 200 (the radio communicationprocessing unit 231) receives the local identification information asthe resource allocation information, from the base station 100.

Moreover, the radio resources within a region in the frequency bandoutside the bandwidth part may also have different local identificationinformation for locally identifying the radio resources within theregion. In this case, the base station 100 (the radio communicationprocessing unit 141) may transmit the different local identificationinformation as the resource allocation information, to the terminalapparatus 200. The terminal apparatus 200 (the radio communicationprocessing unit 231) may receive the different local identificationinformation as the resource allocation information, from the basestation 100.

FIG. 10 is an explanatory diagram for illustrating an example of localidentification information according to the first example embodiment.With reference to FIG. 10, a frequency band including eight resourceblocks (RBs #0 to #7) is illustrated as in the example in FIG. 7. Alsoin this example, as in the example in FIG. 7, a band including RBs #2 to#5 is a bandwidth part, radio resources within the bandwidth part beingallocable for communication using DFT-S-OFDM. As indicated inparentheses, RBs #2 to #5 within the bandwidth part has respectivepieces of local identification information #0 to #3. For example, asresource allocation information for the terminal apparatus 200A, localidentification information of the first RB among allocated RBs andinformation indicating the number of allocated RBs (or localidentification information of the last RB among the allocated RBs) aretransmitted to the terminal apparatus 200A. Moreover, in this example,RBs #0, #1, #6, and #7 in the regions outside the bandwidth part alsohave #0 to #3, respectively, as pieces of different local identificationinformation for locally identifying RBs #0, #1, #6, and #7 in theregions. For example, as resource allocation information for theterminal apparatus 200B, the different local identification informationis transmitted to the terminal apparatus 200B. In this way, it may bepossible to reduce the information amount of resource allocationinformation.

Note that the local identification information is not limited toinformation indicating each individual RB as described above. Forexample, the local identification information may be informationindicating a combination of RBs. For example, as illustrated in FIG. 11,it is possible to identify, by using a tree-based representation,combinations of contiguous RBs among RBs #0 to #7 by using indices 0 to35. In the case of using such a tree-based representation, for example,radio resources (a combination of contiguous RBs) within the bandwidthpart (RBs #2 to #5) may have one of indices 0 to 9 as localidentification information as illustrated in FIG. 12. In this way, forexample, the information amount of the resource allocation informationis reduced from six bits (for 0 to 35) to four bits (for 0 to 9).

As described above, it is possible, for example, to reduce the overheadof resource allocation information by using local identificationinformation.

The DCI may be transmitted on a physical downlink control channel(PDCCH) or may be transmitted on a machine type communications PDCCH(MPDCCH).

For example, the format of DCI may be Format 6-0A, 6-0B, 6-1A, 6-1B, or6-2. In this case, DCI may include a repetition number for a PDSCH or aPUSCH.

When DCI includes a repetition number, a system may be configured so asto dynamically switch at least one of the first control information andthe second control information every subframes corresponding to therepetition number. Moreover, DCI may include control informationindicating that at least one of the first control information and thesecond control information is dynamically switched every subframescorresponding to the repetition number. Note that at least one of thefirst control information and the second control information may bedifferent among subframes in which the at least one of the first controlinformation and the second control information is repeatedlytransmitted, and control information indicating this may be included inDCI.

(6) Transmission of Control Information to Different Base Station

For example, the base station 100 (the network communication processingunit 143) transmits third control information indicating the bandwidthpart, to a different base station.

More specifically, for example, the base station 100 (the networkcommunication processing unit 143) transmits a message including thethird control information, to the different base station through an Xninterface. The message may further include different kinds ofinformation indicating the term of validity and the like of the thirdcontrol information. The message may be a message for interferencecontrol or CoMP.

With this, for example, it is possible to perform interference controlor CoMP more appropriately between base stations even when two radiotransmission schemes coexist.

(7) Measurements

As described above, for example, the communication using the first radiotransmission scheme and the communication using the second radiotransmission scheme are each uplink communication.

For example, the terminal apparatus 200 (the radio communicationprocessing unit 231) transmits uplink reference signals for measurementswithin the bandwidth part and does not transmit the uplink referencesignals outside the bandwidth part, when performing uplink communicationusing the second radio transmission scheme within the bandwidth part. Inother words, transmission of uplink reference signals is restricted tobe performed within the bandwidth part (e.g., RBs #2 to #5). Forexample, the measurements are measurements of channel quality by thebase station 100. With this, it is possible, for example, to improveaccuracy in measurements of channel quality by the base station 100.

(8) Flow of Processing

With reference to FIG. 13, a description will be given of an example ofcommunication processing according to the first example embodiment. FIG.13 is a sequence diagram for illustrating an example of a schematic flowof communication processing according to the first example embodiment.

The base station 100 transmits first control information indicating abandwidth part, to the terminal apparatus 200 (S301). The terminalapparatus 200 receives the first control information from the basestation 100. For example, the base station 100 transmits an RRC message(or a MAC control element) including the first control information.

The base station 100 transmits, to the terminal apparatus 200, secondcontrol information indicating which of the first radio transmissionscheme and the second radio transmission scheme is used and the resourceallocation information (S303). The terminal apparatus 200 receives thesecond control information and the resource allocation information fromthe base station 100. For example, the base station 100 transmits DCIincluding the second control information and the resource allocationinformation.

The terminal apparatus 200 transmits data to the base station 100, basedon the first control information, the second control information, andthe resource allocation information (S305). The base station 100receives the data.

3.5. Example Alterations

Next, with reference to FIG. 14, example alterations of the firstexample embodiment will be described.

(1) First Example Alteration

As described above, for example, the bandwidth part is a band withinwhich radio resources are not allocable for communication of the firstradio transmission scheme. However, the first example embodiment is notlimited to this example.

As a first example alteration of the first example embodiment, thebandwidth part may be a band within which radio resources are allocablealso for communication of the first radio transmission scheme. In otherwords, the base station 100 (the radio communication processing unit141) and the terminal apparatus 200 (the radio communication processingunit 231) may perform communication using the first radio transmissionscheme also within the bandwidth part without being limited to within aregion of the frequency band outside the bandwidth part. In this case,for example, the bandwidth part may be a band within which radioresources are allocated more preferentially for communication of thesecond radio transmission scheme than for communication of the firstradio transmission scheme.

FIG. 14 is an explanatory diagram for illustrating an example ofresource allocation according to the first example alteration of thefirst example embodiment. With reference to FIG. 14, a frequency bandincluding eight resource blocks (RBs #0 to #7) is illustrated as in theexample in FIG. 7. Also in this example, as in the example in FIG. 7, aband including RBs #2 to #5 is a bandwidth part, radio resources withinthe bandwidth part being allocable for communication using DFT-S-OFDM.In particular, in the first example alteration, radio resources in allRBs #0 to #7, instead of only RBs #0, #1, #6, and #7, are allocable forcommunication using OFDM. However, RBs #2 to #5 are preferentiallyallocated for communication using DFT-S-OFDM.

With this, for example, it is possible to use radio resources whilewasting less.

(2) Second Example Alteration

As described above, for example, the frequency band is a system band ofa cellular system or a component carrier. However, the first exampleembodiment is not limited to this example.

As a second example alteration of the first example embodiment, thefrequency band may be part of a system band or a component carrier. Thispart may be a band corresponding to the maximum transmission bandwidth(or the maximum reception bandwidth) of the terminal apparatus 200.

(3) Third Example Alteration

As described above, for example, the communication using the first radiotransmission scheme and the communication using the second radiotransmission scheme are each uplink communication. However, the firstexample embodiment is not limited to this example.

As a third example alteration of the first example embodiment, thecommunication using the first radio transmission scheme and thecommunication using the second radio transmission scheme may each bedownlink communication.

In this case, for example, the terminal apparatus 200 (the radiocommunication processing unit 231) may measure channel quality for thebandwidth part and may not necessarily measure channel quality for theother band(s) of the frequency band. In other words, the band in whichthe terminal apparatus 200 performs measurements is restricted withinthe bandwidth part (e.g., RBs #2 to #5). The terminal apparatus 200transmits a result of the measurements within the bandwidth part asfeedback to the base station 100. With this, it is possible, forexample, to reduce a computation amount for measurements by the terminalapparatus 200 and reduce the overhead of feedback with a measurementresult.

The first example embodiment has been described above. According to thefirst example embodiment, it is possible, for example, to performcontrol related to radio communication more appropriately when radiotransmission schemes coexist.

4. Second Example Embodiment

Next, a description will be given of a second example embodiment of thepresent invention with reference to FIG. 15. The above-described firstexample embodiment is a concrete example embodiment, whereas the secondexample embodiment is a more generalized example embodiment.

4.1. Configuration of Radio Communication Apparatus

First, with reference to FIG. 15, an example of a configuration of aradio communication apparatus 400 according to the second exampleembodiment will be described. FIG. 15 is a block diagram illustrating anexample of a schematic configuration of the radio communicationapparatus 400 according to the second example embodiment. With referenceto FIG. 15, the radio communication apparatus 400 includes a radiocommunication processing unit 410.

Concrete operations of the radio communication processing unit 410 willbe described later in detail.

The radio communication processing unit 410 may be implemented with oneor more processors (such as a BB processor and/or a different kind ofprocessor) and a memory. The memory may be included in the one or moreprocessors or may be provided outside the one or more processors. As anexample, the radio communication processing unit 410 may be implementedwithin a SoC.

The radio communication apparatus 400 may include a memory configured tostore a program (instructions) and one or more processors that canexecute the program (instructions). The one or more processors mayexecute the program and thereby perform operations of the radiocommunication processing unit 410. The program may be a program forcausing the processor(s) to perform the operations of the radiocommunication processing unit 410.

The radio communication apparatus 400 may be virtual. In other words,the radio communication apparatus 400 may be implemented as a virtualmachine. In this case, the radio communication apparatus 400 (virtualmachine) may operate as a physical machine (hardware) including aprocessor, a memory, and the like, and a virtual machine on ahypervisor.

Note that the radio communication apparatus 400 may, of course, furtherinclude constituent elements other than the radio communicationprocessing unit 410. For example, the radio communication apparatus 400,as in the first example embodiment, may further include a radiocommunication unit, a network communication unit (and a networkcommunication processing unit) and/or a storage unit, and/or may furtherinclude other constituent elements.

4.2. Technical Features

Next, technical features of the second example embodiment will bedescribed.

The radio communication apparatus 400 (the radio communicationprocessing unit 410) performs communication using a first radiotransmission scheme, within the frequency band. Moreover, the radiocommunication apparatus 400 (the radio communication processing unit410) performs communication using a second radio transmission schemewithin a bandwidth part of the frequency band, radio resources withinthe bandwidth part being allocable for communication using the secondradio transmission scheme.

For example, the radio communication apparatus 400 is a base station. Asan example, the radio communication apparatus 400 is the base station100 according to the first example embodiment. The radio communicationapparatus 400 may, of course, be a different base station.

Alternatively, the radio communication apparatus 400 may be a terminalapparatus. As an example, the radio communication apparatus 400 may bethe terminal apparatus 200 according to the first example embodiment.The radio communication apparatus 400 may, of course, be a differentterminal apparatus.

As an example, descriptions of radio transmission schemes,communication, a frequency band, a bandwidth part, transmission ofcontrol information to a terminal apparatus, transmission of controlinformation to a different base station, measurements, and a flow ofprocessing are the same as the descriptions in the first exampleembodiment. Hence, overlapping descriptions are omitted here. Note that,in this case, the radio communication processing unit 410 may operatesimilarly to the radio communication processing unit 141 or the radiocommunication processing unit 231 of the first example embodiment.

The second example embodiment is, of course, not limited to thisexample.

The second example embodiment has been described above. According to thesecond example embodiment, it is possible, for example, to performcontrol related to radio communication more appropriately when radiotransmission schemes coexist.

Descriptions have been given above of the example embodiments of thepresent invention. However, the present invention is not limited tothese example embodiments. It should be understood by those of ordinaryskill in the art that these example embodiments are merely examples andthat various alterations are possible without departing from the scopeand the spirit of the present invention.

For example, the steps in the processing described in the Specificationmay not necessarily be carried out in time series in the order describedin the corresponding sequence diagram. For example, the steps in theprocessing may be carried out in an order different from that describedin the corresponding sequence diagram or may be carried out in parallel.Some of the steps in the processing may be deleted, or more steps may beadded to the processing.

An apparatus including constituent elements (e.g., the radiocommunication processing unit and/or the network communicationprocessing unit) of the base station described in the Specification(e.g., one or more apparatuses (or units) among a plurality ofapparatuses (or units) constituting the base station or a module for oneof the plurality of apparatuses (or units)) may be provided. Anapparatus including the constituent elements (e.g., the radiocommunication processing unit) of the terminal apparatus described inthe Specification (e.g., a module for the terminal apparatus) may beprovided. Moreover, methods including processing of the constituentelements may be provided, and programs causing a processor to executeprocessing of the constituent elements may be provided. Moreover,non-transitory computer readable recording media (non-transitorycomputer readable media) having recorded thereon the programs may beprovided. It is apparent that such apparatuses, modules, methods,programs, and non-transitory computer readable recording media are alsoincluded in the present invention.

The whole or part of the example embodiments disclosed above can bedescribed as, but not limited to, the following supplementary notes.

Supplementary Note 1

A radio communication apparatus comprising:

a radio communication processing unit configured to performcommunication using a first radio transmission scheme within a frequencyband,

wherein the radio communication processing unit is configured to performcommunication using a second radio transmission scheme within abandwidth part of the frequency band, radio resources within thebandwidth part being allocable for communication using the second radiotransmission scheme.

Supplementary Note 2

The radio communication apparatus according to Supplementary Note 1,wherein

the first radio transmission scheme is a multi-carrier transmissionscheme, and

the second radio transmission scheme is a single-carrier transmissionscheme.

Supplementary Note 3

The radio communication apparatus according to Supplementary Note 1 or2, wherein

the first radio transmission scheme is a first multiplexing scheme, and

the second radio transmission scheme is a second multiplexing scheme.

Supplementary Note 4

The radio communication apparatus according to any one of SupplementaryNotes 1 to 3, wherein

the first radio transmission scheme is Orthogonal Frequency DivisionMultiplexing (OFDM), and

the second radio transmission scheme is Discrete Fourier TransformSpread Orthogonal Frequency Division Multiplexing (DFT-S-OFDM).

Supplementary Note 5

The radio communication apparatus according to any one of SupplementaryNotes 1 to 4, wherein the bandwidth part is a band within which radioresources are not allocable for communication of the first radiotransmission scheme.

Supplementary Note 6

The radio communication apparatus according to any one of SupplementaryNotes 1 to 4, wherein the bandwidth part is a band within which radioresources are allocable for communication of the first radiotransmission scheme.

Supplementary Note 7

The radio communication apparatus according to Supplementary Note 6,wherein the bandwidth part is a band within which radio resources areallocated more preferentially for communication of the second radiotransmission scheme than for communication of the first radiotransmission scheme.

Supplementary Note 8

The radio communication apparatus according to any one of SupplementaryNotes 1 to 7, wherein the radio communication apparatus is a basestation.

Supplementary Note 9

The radio communication apparatus according to Supplementary Note 8,wherein the radio communication processing unit is configured totransmit, to a terminal apparatus, first control information indicatingthe bandwidth part.

Supplementary Note 10

The radio communication apparatus according to Supplementary Note 9,wherein the radio communication processing unit is configured totransmit, to a terminal apparatus, a radio resource control (RRC)message or a medium access control (MAC) control element including thefirst control information.

Supplementary Note 11

The radio communication apparatus according to Supplementary Note 9 or10, wherein

a radio resource within the bandwidth part has local identificationinformation for locally identifying the radio resource within thebandwidth part, and

the radio communication processing unit is configured to transmit, to aterminal apparatus, the local identification information as resourceallocation information.

Supplementary Note 12

The radio communication apparatus according to any one of SupplementaryNotes 8 to 11, wherein the radio communication processing unit isconfigured to transmit, to a terminal apparatus, second controlinformation indicating which of the first radio transmission scheme andthe second radio transmission scheme is used.

Supplementary Note 13

The radio communication apparatus according to Supplementary Note 12,wherein the radio communication processing unit is configured totransmit, to a terminal apparatus, downlink control information (DCI)including the second control information.

Supplementary Note 14

The radio communication apparatus according to any one of SupplementaryNotes 8 to 13, further comprising a network communication processingunit configured to transmit, to another base station, third controlinformation indicating the bandwidth part.

Supplementary Note 15

The radio communication apparatus according to any one of SupplementaryNotes 1 to 7, wherein the radio communication apparatus is a terminalapparatus.

Supplementary Note 16

The radio communication apparatus according to Supplementary Note 15,wherein the radio communication processing unit is configured toreceive, from a base station, first control information indicating thebandwidth part.

Supplementary Note 17

The radio communication apparatus according to Supplementary Note 16,wherein

a radio resource within the bandwidth part has local identificationinformation for locally identifying the radio resource within thebandwidth part, and

the radio communication processing unit is configured to receive, from abase station, the local identification information as resourceallocation information.

Supplementary Note 18

The radio communication apparatus according to any one of SupplementaryNotes 15 to 17, wherein the radio communication processing unit isconfigured to receive, from a base station, second control informationindicating which of the first radio transmission scheme and the secondradio transmission scheme is used.

Supplementary Note 19

The radio communication apparatus according to any one of SupplementaryNotes 15 to 18, wherein

the communication using the first radio transmission scheme and thecommunication using the second radio transmission scheme are uplinkcommunication, and

the radio communication processing unit is configured to transmit uplinkreference signals for measurements within the bandwidth part and not totransmit the uplink reference signals outside the bandwidth part, whenperforming uplink communication using the second radio transmissionscheme within the bandwidth part.

Supplementary Note 20

The radio communication apparatus according to any one of SupplementaryNotes 15 to 18, wherein

the communication using the first radio transmission scheme and thecommunication using the second radio transmission scheme are downlinkcommunication, and

the radio communication processing unit is configured to measure channelquality for the bandwidth part and not to measure channel quality forthe other bands of the frequency band.

Supplementary Note 21

The radio communication apparatus according to any one of SupplementaryNotes 1 to 18, wherein the communication using the first radiotransmission scheme and the communication using the second radiotransmission scheme are uplink communication.

Supplementary Note 22

The radio communication apparatus according to any one of SupplementaryNotes 1 to 18, wherein the communication using the first radiotransmission scheme and the communication using the second radiotransmission scheme are downlink communication.

Supplementary Note 23

The radio communication apparatus according to any one of SupplementaryNotes 1 to 22, wherein the communication using the first radiotransmission scheme and the communication using the second radiotransmission scheme are communication of data channel.

Supplementary Note 24

The radio communication apparatus according to any one of SupplementaryNotes 1 to 23, wherein the bandwidth part has a bandwidth equal to orwider than two resource blocks.

Supplementary Note 25

The radio communication apparatus according to any one of SupplementaryNotes 1 to 24, wherein the bandwidth part has a bandwidth wider than 1.4MHz.

Supplementary Note 26

The radio communication apparatus according to any one of SupplementaryNotes 1 to 25, wherein the frequency band is a frequency band of acellular system.

Supplementary Note 27

The radio communication apparatus according to any one of SupplementaryNotes 1 to 26, wherein the frequency band is a system band or acomponent carrier.

Supplementary Note 28

A method comprising

performing communication using a first radio transmission scheme withina frequency band; and

performing communication using a second radio transmission scheme withina bandwidth part of the frequency band, radio resources within thebandwidth part being allocable for communication using the second radiotransmission scheme.

Supplementary Note 29

A program that causes a processor to execute:

performing communication using a first radio transmission scheme withina frequency band; and

performing communication using a second radio transmission scheme withina bandwidth part of the frequency band, radio resources within thebandwidth part being allocable for communication using the second radiotransmission scheme.

Supplementary Note 30

A non-transitory computer readable recording medium having recordedthereon a program that causes a processor to execute:

performing communication using a first radio transmission scheme withina frequency band; and

performing communication using a second radio transmission scheme withina bandwidth part of the frequency band, radio resources within thebandwidth part being allocable for communication using the second radiotransmission scheme.

Supplementary Note 31

A system comprising:

a base station; and

a terminal apparatus,

wherein the base station is configured to:

-   -   perform communication using a first radio transmission scheme        within a frequency band; and    -   perform communication using a second radio transmission scheme        within a bandwidth part of the frequency band, radio resources        within the bandwidth part being allocable for communication        using the second radio transmission scheme, and

wherein the terminal apparatus is configured to:

-   -   perform communication using the first radio transmission scheme        within the frequency band; and    -   perform communication using the second radio transmission scheme        within the bandwidth part.

INDUSTRIAL APPLICABILITY

It is possible to perform control related to radio communication moreappropriately when radio transmission schemes coexist, in a mobilecommunication system (cellular system).

REFERENCE SIGNS LIST

1 System

100 Base Station

141 Radio Communication Processing Unit

143 Network Communication Processing Unit

200 Terminal Apparatus

231 Radio Communication Processing Unit

400 Radio Communication Apparatus

410 Radio Communication Processing Unit

What is claimed is:
 1. A radio communication apparatus comprising: amemory storing instructions; and one or more processors configured toexecute the instructions to: perform communication using a first radiotransmission scheme within a frequency band; and perform communicationusing a second radio transmission scheme within a bandwidth part of thefrequency band, radio resources within the bandwidth part beingallocable for communication using the second radio transmission scheme.2. The radio communication apparatus according to claim 1, wherein thefirst radio transmission scheme is a multi-carrier transmission scheme,and the second radio transmission scheme is a single-carriertransmission scheme.
 3. The radio communication apparatus according toclaim 1, wherein the first radio transmission scheme is a firstmultiplexing scheme, and the second radio transmission scheme is asecond multiplexing scheme.
 4. The radio communication apparatusaccording to claim 1, wherein the first radio transmission scheme isOrthogonal Frequency Division Multiplexing (OFDM), and the second radiotransmission scheme is Discrete Fourier Transform Spread OrthogonalFrequency Division Multiplexing (DFT-S-OFDM).
 5. The radio communicationapparatus according to claim 1, wherein the bandwidth part is a bandwithin which radio resources are not allocable for communication of thefirst radio transmission scheme.
 6. The radio communication apparatusaccording to claim 1, wherein the bandwidth part is a band within whichradio resources are allocable for communication of the first radiotransmission scheme.
 7. The radio communication apparatus according toclaim 6, wherein the bandwidth part is a band within which radioresources are allocated more preferentially for communication of thesecond radio transmission scheme than for communication of the firstradio transmission scheme.
 8. The radio communication apparatusaccording to claim 1, wherein the radio communication apparatus is abase station.
 9. The radio communication apparatus according to claim 8,wherein the one or more processors are configured to execute theinstructions to transmit, to a terminal apparatus, first controlinformation indicating the bandwidth part.
 10. The radio communicationapparatus according to claim 9, wherein the one or more processors areconfigured to execute the instructions to transmit, to a terminalapparatus, a radio resource control (RRC) message or a medium accesscontrol (MAC) control element including the first control information.11. The radio communication apparatus according to claim 8, wherein theone or more processors are configured to execute the instructions totransmit, to a terminal apparatus, second control information indicatingwhich of the first radio transmission scheme and the second radiotransmission scheme is used.
 12. The radio communication apparatusaccording to claim 11, wherein the one or more processors are configuredto execute the instructions to transmit, to a terminal apparatus,downlink control information (DCI) including the second controlinformation.
 13. The radio communication apparatus according to claim 8,the one or more processors are configured to execute the instructions totransmit, to another base station, third control information indicatingthe bandwidth part.
 14. The radio communication apparatus according toclaim 1, wherein the radio communication apparatus is a terminalapparatus.
 15. The radio communication apparatus according to claim 14,wherein the one or more processors are configured to execute theinstructions to receive, from a base station, first control informationindicating the bandwidth part.
 16. The radio communication apparatusaccording to claim 14, wherein the one or more processors are configuredto execute the instructions to receive, from a base station, secondcontrol information indicating which of the first radio transmissionscheme and the second radio transmission scheme is used.
 17. The radiocommunication apparatus according to claim 14, wherein the communicationusing the first radio transmission scheme and the communication usingthe second radio transmission scheme are uplink communication, and theone or more processors are configured to execute the instructions totransmit uplink reference signals for measurements within the bandwidthpart and not to transmit the uplink reference signals outside thebandwidth part, when performing uplink communication using the secondradio transmission scheme within the bandwidth part.
 18. The radiocommunication apparatus according to claim 14, wherein the communicationusing the first radio transmission scheme and the communication usingthe second radio transmission scheme are downlink communication, and theone or more processors are configured to execute the instructions tomeasure channel quality for the bandwidth part and not to measurechannel quality for the other bands of the frequency band.
 19. A methodcomprising performing communication using a first radio transmissionscheme within a frequency band; and performing communication using asecond radio transmission scheme within a bandwidth part of thefrequency band, radio resources within the bandwidth part beingallocable for communication using the second radio transmission scheme.20. A system comprising: a base station; and a terminal apparatus,wherein the base station is configured to: perform communication using afirst radio transmission scheme within a frequency band; and performcommunication using a second radio transmission scheme within abandwidth part of the frequency band, radio resources within thebandwidth part being allocable for communication using the second radiotransmission scheme, and wherein the terminal apparatus is configuredto: perform communication using the first radio transmission schemewithin the frequency band; and perform communication using the secondradio transmission scheme within the bandwidth part.